pandas - DataFrameEditor in traitsUI only displays index -

i investigating dataframeeditor in traitsui. came across odd behaviour , hoped confirm and/or offer solution.

if run minimal example below:

import numpy np import pandas pd  traits.api import hasstricttraits, instance, button  traitsui.api import view, item, vgroup  traitsui.ui_editors.data_frame_editor import dataframeeditor  class foo(hasstricttraits):      do_it = button(label='do it')     data = instance('pandas.core.frame.dataframe')      view = view(                 vgroup(                        item('data', show_label=false,                              editor=dataframeeditor(editable=true)),                        item('do_it', show_label=false)                        )                 )      def _data_default(self):         return pd.dataframe()      def _do_it_fired(self):         self.data = pd.dataframe({'a': np.arange(5),                                   'b': np.arange(5)})  if __name__=='__main__':     f = foo()     f.configure_traits() 

then first time hit do it button see index of dataframe:

index only

which not right. if close window , re-run e.configure_traits() see full dataframe expected:

full dataframe

is bug? doing wrong?